The present invention relates, in general, to medical and surgical apparatus for the collection of fluids, and more particularly to containers for receiving fluids from surgical patients.
As is well-known, during the course of a surgical operation on a patient, it is often necessary to remove from the site of the operation various body fluids, including blood, which tend to collect there. Removal of such body fluids is generally accomplished by means of an aspirator device which utilizes a vacuum to draw the fluids through a suitable tube for deposit in a collection bottle or jar. Body fluid storage bottles for use in such systems are well-known in the art, but have not been entirely satisfactory, since they have often been complex to assemble and use, expensive, and often unreliable in operation.
In an aspirator system, the vacuum which draws the fluid is produced in the fluid collection jar by some suitable means such as a central vacuum pump, thus causing a negative pressure in the tube leading to the patient from whom fluids are to be withdrawn. This vacuum draws the fluid through the drainage tube to the inlet port of the collection bottle. Since it is important in many cases to be able to monitor the flow of such fluids, it is important to measure the amount of fluid collected in the aspirator jar. For this purpose, the prior art has provided means for carrying this fluid to the bottom of the collection container, so that the inlet fluid does not splash and create a foam which would interfere with the volume measurements. However, such splash tubes have been found to create an additional problem, in that they can act as a siphon if for any reason the vacuum is lost and carry the aspirated fluids back to the operation site. Despite efforts to reduce the siphon effect, malfunction and flowback into the patient remains a serious problem.
Other problems found in prior art devices include a danger of contamination of the vacuum system by entrainment of moisture or small particles of solid matter. In addition, prior art devices have traditionally been constructed with walls of sufficient thickness to withstand substantial negative pressures without danger of implosion. Thin-walled collection vessels which are very desirable for economic reasons have generally been prone to malfunction as a result of implosion or cracking with resultant spillage of fluid and contamination of the operating area. Thus the availability of a thin-wall container with adequate protection against implosion, vacuum system contamination, and siphon flowback has become a major operating room need.